Turbine blade attachment by welding



W. HUBER TURBINE BLADE ATTACHMENT BY WELDING Sept. 18, 1945.

Filed Aug. 25, 1945 2 Sheets-Sheet 1 Sept. 18,1945. w. HUBER I 2,384,919

TURBINE BLADE ATTACHMENT BY WELDING Filed Aug. 25, 1943 2 Sheets-Sheet 2 INVENTOR ATTORNEYS Patented Sept. 18, 1945 UNITED STATES PATENT OFFICE TURBINE BLADE ATTACHMENT BY I WELDING Walter Haber, Wlnterthur, Switserland, aasigner Y m Mannie. Winterthur,

lwltles'lanl Application Audit 35, 1.48. Serial No. "0,11

' lwitserlanll Novemba- 5, 1042 4 a claims. (ct ass-m The invention relates to a oi.

any application having blades attached to the blade carrier by welding. The distinguishing characteristic of the invention consists in that the blade roots are iork-shaped design. are ntted astraddle over a ring situated in a groove of the blade carrier and are welded'tc the blade carrier at the points of the forks.

Figs. 9 and 10 show a cross-section and a ground plan of a clamping device for the blades during It is advantageous m the ring to be provided not only with one or more rigidsupporting shoulders but also with one or more yielding supporting shoulders, in such a way that the blades lie upon the yielding shoulders beiorewelding, while after welding; on account of the forces exerted by the shrinkage of the cooling.

weld and of the resulting deformation of the yielding shoulders, they are pressed on to the rigid shoulders of the ring.

To iaciiitate insertion into the groove ofthe blade carrier it is preferabl that the ring be divided in a radial direction at one or more points on its circumference. The ring mayalso have one or more divisions in a direction at right angiestothe axis. Eachpartmaybepmvided with one or more rigid oneor more yielding shoulders. The yielding shoulders ofboth parts may then be situated between the rigid shoulders ofbothperts.

'I'heopposingilanksoi'thebladerootsmayto advantase be stepped in such a way that, alter weldinnthebladeaareincontactoniyatthe unltepped parts. After welding it is advisable to cioseupthe spaces formed blthdm.

The blade roots should be so divided that, beiore welding. a space remains between the blades .andalsobetweentheunsteppedpartsoftheroots,

which space disappears or almost diaappearsas Y aresultoishrinkasewhencoolingsetsinafter gwelding,the blades maybe new mule correct position by a clamping device. The blades may, for example. he provided with projecting edgeswiththehelpofwhichtheyareheldbythe clamping device during welding. v a The invention is iurther explained below with theaidofthtdrlm welding."

The rotor according to Figs. '1 and 2. which may be equally well employed for a turbine or for an axial compr and sections 2 of the axis. The single rotor parts are connected to each other by welded scams 8-. Each disc has around its circumference a groove ,mwhicharlngliaplaced.

The blades t have roots I designed in forked form, with which they are set astreddle over ring I. By means or the welded seams I blades 0 are ilnally joined to the discs. attheir forked points.

The opposing flanks 0 (Figs. 3 and 4) of the blade roots I are stepped at surfaces ll, so that they can only touch at the unstepped parts ii. The spaces It formed by the stepp nz can be tilled after welding with inserted pieces, which are secured against falling out by caulking. Ring I is divided in a radial direction at point It in order to facilitate insertion into the groove. The ring can be sprung open and pushed over the outer v circumierence of the discs into the groove.

'lhebladeeaccordingtol'issotodareplaced overaringlwhichisdividedatrishtanslesto l'igalandlshowpartlyalongihidhialeection' I and partly a side. elevation or front elevationof a simplified example of execution.

Pigl- Sand'trepresentintwo projections at 'rightanglestoeachotherandonalarser-scale the blade execution of the turbo-machine accord I instnllsaiands.

mttoashowanotlierrormofbiadeenecn- T ticnbeioreandalterweldins.

theaxis'atpoint ll. Eachpertoftheringis provided with two rigid shoulders II and two yielding shoulders II. The yielding shoulders II are situated between the rigid shoulders it. Be--.

fore welding (Figs. 5 and 6).the blades rest-on .theyielding shoulders is. Bimllarlythe rlngerest withtheiryieldingshouldersonthebotmm surface of the groove.

'lhe shoulders are so designed and -propor-- notonly'theweldniembutalsothebasiclnetal clsoniscomposedofdiscsi- 2" ascetic shrinkagewhichaccompaniescoolingthesiiaces ybetweenilanks H willalsodisappearoralmost disappear, so that the blades alter welding all. winpracticallylielninsteachother.

Duringweldingtheblades areheldintheooh' rect position by a clamping device ll (Figs. 9 and 10). Each blade is provided before welding with After welding, as is shown for example in Figs. 1' Y 3 and 7, both the projecting edge on the blades and the outer part or the welded seam can be removed by machining, for example by turning.

Hence it follows that the blades, are first welded on, then the machining oi the disc is completed and only after this are the finished discs with their blades connected together to form a rotor.

In the manner described it is possible to attach all possible kinds of blades oi turbo-machines, such as also blades of turbo-machines with radial ilow, to the blade carrier, and the invention can be equally well applied to impeller or to guide blades.

I claim:

1. A turbo-machine which comprises at least one disc, a groove in the periphery of the disc, a ring mounted in the groove, said ring having rigid supporting shoulders and yielding supporting shoulders, a plurality of blades each having a groove in its root for mounting the blades astraddle over the ring, means to weld the blades to the disc on each side or the ring, so that prior to welding said blades lie on the yielding shoulders and after welding and contracting said blades lie on the rigid shoulders, and spacer means between adjacent blades to permit circumferential shrinkage after welding.

2. A turbo-machine according to claim 1 in which said ring is divided in a radial direction at one or more points on its circumference.

3. A turbo-machine according to claim 1 in which said ring has one or more divisions in a direction at right angles to the axis.

4. A turbo-machine according to claim 1 in whichsaidringhasarisidsupportingshoulder neareachsideedgethereoi'andsyieldingshoulder located between the ri id shoulders, said shoulders being on the periphery of the ring.

6. A turbo-machine according to claim 1 in which said blade roots have radially disposed contacting laces which are stepped whereby contact ing blade roots have a'cutout portion.

8.Aturbo-machineaccordingtoclaim lin which each or said blades has a projecting edge on the exterior side to engage a clamping means usedtosecm'ethebladesduringwelding.

7. A turbo-machine which comprises at least onedise, a groove in the periphery of the disc, a ring mounted in the groove, a plurality of blades each having a groove in its root for mounting f the blades astraddle over the ring, said ring having at least one rigid shoulder on the interior periphery for engaging the disc and at least one rigid shoulder on the exterior periphery for engaging the blades and yielding means for supporting said blades during welding, means for welding the blades to the side portions oi. the disc so that prior to welding said yielding means support the blades spaced from the disc and alter welding yield permitting the rigid shoulder on the interior to lie on the disc and blades to lie on the rigid shoulders, and spacer means between the adjacent faces oi the blade roots prior to welding which close as a result of the contracting following welding.

8. A turbo-machine which comprises at least one disc, a groove in the periphery of the disc, a ring mounted in the groove, a plurality oi blades each having a groove in its root for mounting the blades astraddle over the ring, said ring having at least one rigid shoulder on the interior periphery tor engaging the disc and at least one rigid shoulder on the exterior periphery for engaging the blades and yielding means for supporting said blades during welding, and means for welding the blades to the side portions of the disc, so that prior to welding said yielding means support the blades spaced from the disc and 4 after welding yield permitting the rigid shoulder on the interior to lie on the disc and blades to lie on the riirld shoulders.

WALTER HUBER. 

